In U.S. patent application Ser. No. 11/067,525, filed Feb. 25, 2005, for “Projectile Barrier and Method”, now U.S. Pat. No. 7,169,452 B1, granted Jan. 30, 2007, a special kind of leakage-defeating protective coating for a liquid container is illustrated and described. The content of this U.S. Patent is also hereby incorporated herein by reference for background information purposes.
Fundamentally, that U.S. patent ('452) describes a unique, plural-layer, anti-leakage protective coating which may be applied to the surface of a metallic liquid container, such as to the surface of a metal (steel or aluminum) tank holding hydrocarbon fuel. In the described layer structure of this coating, two different kinds of layers are disclosed and discussed, one of which is formed substantially purely of a high-elastomeric material, and the other of which is a composite material formed of the same high-elastomeric material just mentioned in which there additionally resides a distribution of liquid-imbiber bead-like elements, or beads. Both of these materials are referred to herein as penetration-reaction materials. The high-elastomeric material is referred to also as a body-forming material.
The present invention concerns itself principally with a spray-application manner for creating the second-mentioned one of these two types of layers, namely, for creating the composite-material layer which includes both an elastomeric body, and a distribution therein of liquid-imbiber beads.
According to a preferred practice of the invention, the desired composite-material layer is formed by merging in air, as what is referred to herein as a sprayed-layer blend, and just before application to a target surface on a target liquid container, i.e., en route to that surface) of two independently sprayed streams of material, one of which sprays contains wet, liquid, high-elastomeric material, and the other of which includes dry, liquid-imbiber beads.
As will be learned from the detailed description below, and in relation to the specific, illustrative, composite-material layer shown and described herein, when this detailed description is read along with the accompanying drawings, pre-spray flows of these two kinds of materials are appropriately adjusted relative to one another to end up producing a desired composite-material layer wherein, in the final layer, the sprayed high-elastomeric material accounts for about 78-percent by weight of the layer, and the imbedded, distributed liquid-imbiber beads account for about 22-percent by weight of the final layer.
Additionally, and in accordance with practice of the invention, a user is offered the option of adjusting, differentially, the relative positions of two spray heads which are employed to create, selectively, different characters of air-blended sprays of the two different layer-forming materials. This position adjustability feature allows for both changing the lateral separation between these two spray heads, one for each of the two materials, and also for allowing what is referred to herein as relative longitudinal adjustment so as to position one spray head or the other closer to or further away from an intended target surface where layer formation is to take place. This control adjustability allows a user a relatively wide range of options for composite-material layer formation. It does so by varying the length of time that initially dry liquid-imbiber beads are in contact with still-uncured still-liquid elastomeric material.
Further included in the invention methodology are several proposed and different modalities for delivering the liquid imbiber beads to the associated spray instrumentality (head) which creates a spray of these beads. Included in these modalities, as will seen, are gravity, auger-drive feed, and compressed-air assistance (where desired).
Various other features and advantages that are offered by the present invention will now become more fully apparent as the detailed description of the invention which follows is read in conjunction with the accompanying drawings.